Sarcoptic Mange of Dogs

Dogs have many parasites, both internal and external. Internal parasites are those which live in the various organs inside the dog's body. External parasites, such as fleas, ticks, and mites, live on the outside of the body.

Mange is a parasitic skin disease caused by microscopic mites. Two different types of mange mites are significant in dogs. One type lives in the hair follicles of the skin (demodex or red mange), while the other type resides just under the surface of the skin (Sarcoptic).  Although both types of mites share some similar characteristics, there are also important differences. It is important not to confuse the two types of mange because they have different causes, treatments, and prognoses.

This is a dog with sarcoptic mange

Cats get sarcoptic mange but not very often.  This is a cat with sarcoptic.

Contributing Factors

The sarcoptic mange mite is highly contagious between dogs. Exposure to a dog infested with this mite will likely lead to spread of the parasite.

Prevalence

Sarcoptic mange is a common parasitic skin disease of dogs. Cats get it as well but not as commonly as dogs.

This is a photon micrograph of an adult mite.  Pretty scary to think this can be walking around on you or your dog!

Causes/Transmission
Sarcoptic mange is caused by a mite that burrows just beneath the surface of the skin. It may also crawl around on the skin surface. This mite feeds on material in and on the skin.

This is a drawing of how the female mite burrows in to the skin to lay eggs 

Clinical Signs
The presence of the sarcoptic mite causes severe itching. The dog will chew and scratch its skin constantly. This leads to the loss of large amounts of hair, especially on the legs and belly. Eventually, the skin will become thickened and will darken due to pigmentation. Frequent scratching and rubbing often leads to secondary skin infections.

Diagnosis
A simple at home test for sarcoptic mange is to take the ear of the dog, the flappy part, and rub it between your fingers.  If the dogs back legs starts to pump like it is scratching, that is called a positive pinna/pedal reflex.  That means ear/foot reflex that cannot be stopped. It is kinda like a knee jerk reflex.  When the doctor taps your knee, your leg jerks and you can't stop it.  It is the same with sarcoptic mange and the itch reflex induced by rubbing the ear beween your finger tips.

Your vet uses a by a skin scraping that is examined under the microscope. However, only a small number of mites may be present. Because of this, a dog may be strongly suspected of having sarcoptic mange but multiple skin scrapings are negative. A presumptive diagnosis can be made because the signs are quite typical. Age is not a significant factor in sarcoptic mange. Although most common in puppies, dogs of all ages are at risk.

Treatment
There are several insecticides that are effective against this mite as it is easily killed.    Bangard Dip works great and is very economical.  Bathe the dog in Davis Chlorhexidine Shampoo to remove all flaking skin then saturate the skin with the dip.   Dip once weekly for at least 4 weeks.   Most dogs take 6 weeks to kill off all mites.  
The easiest way to treat is with Ivermectin.   The injectable formulation is given orally.  To find out about ivermect, go to my about me.  AcmeAuctionStuff About Me Page  Ivermectin's ease of administration compared to dipping makes it the drug of choice in certain situations, and it may actually be more effective than dipping in some dogs

Prognosis - will your dog get well?

With appropriate therapy, the prognosis for recovery is excellent. Re-infestation from a contaminated environment or other dogs is possible.

Transmission to Humans

Sarcoptic mange is highly contagious to other dogs; it is also contagious to humans. The dog's bedding should be washed in hot water with bleach or, preferably, discarded. The mites are not able to complete their life cycle on humans; therefore, they will die in a few days without treatment. However, they will cause quite a bit of itching before they finally die.